This page explains how StatPlay (the "Site") handles visitor information.
Last updated: May 30, 2026
// 1. Operator
The Site is operated by Sasai Lab (Junpei Sasai) as a personal project. It does not represent any employer or organization.
// 2. Information collected and purpose
(1) Language preference (functional cookie & local storage)
To remember your display-language choice (Japanese / English), the Site stores your selection in the cookie sp_lang and in browser local storage sp:lang. This is purely functional and contains no personally identifying information.
(2) Analytics (Google Analytics 4)
To understand how the Site is used and to improve its content, the Site uses Google Analytics 4, provided by Google LLC. Google Analytics uses cookies (such as _ga) to collect the following as aggregated statistics:
- Behavioral data such as pages viewed and engagement
- Referral source (which site or search you came from)
- Browser, OS, device type, screen size, and language setting
- Approximate location (estimated from IP address; Google Analytics 4 does not log or store the IP address itself)
This data is aggregated statistically and is not used to identify individuals.
// 3. Third-party data transmission
When you use the Site, visitor information (access data, IP address, environment) is transmitted to the following third-party services. Please review each provider's own privacy policy for how they handle data.
Google Analytics (Google LLC)
Transmitted: cookies and access data / Purpose: analytics
Google Privacy Policy ↗
jsDelivr CDN (delivery of the KaTeX math-rendering library)
The Site loads the KaTeX library used to render mathematical formulas from a CDN (cdn.jsdelivr.net). As a result, your IP address and browser information are sent to the CDN provider.
jsDelivr Privacy Policy ↗
// 4. Managing and disabling cookies
You can refuse or delete cookies through your browser settings. The Site's core features remain usable with cookies disabled, but your language preference may not be retained.
To opt out of Google Analytics collection, you can use Google's Google Analytics Opt-out Browser Add-on ↗.
// 5. Data retention
The functional cookie sp_lang expires after up to two years. The expiry of cookies set by Google Analytics and the retention period of analytics data follow Google's specifications.
// 6. External links
The Site contains links to external websites. The Site is not responsible for how those sites handle information; please review their respective privacy policies.
// 7. Disclosure requests & contact
For questions about this policy, or requests to disclose, correct, or delete collected information, please contact us via GitHub Issues.
GitHub Issues ↗
// 8. Changes to this policy
This policy may be revised in response to changes in law or in the service. Significant changes will be announced on this page.
© 2026 Sasai Lab